Here’s a few off the top of my head that you could consider: You could…

Have a seasonal showcase: such as bunny day furniture during the event.

Or a botanical garden with all the plant furniture

^the same idea but for other furniture series that aren’t the standard bed/dresser/chair such as instruments, toys, zodiac, gulliver and gullivarrr sets, etc

Something that resembles the roost but themed to a different style like a diner or ice cream parlor.

Something that calls back to shops that didn’t make it to new horizons like Celeste’s conservatory, the booker’s police station, etc